The study examines stability and isoperimetry of CMC spheres in hyperbolic and spherical manifolds.
problem Stability and isoperimetry of constant mean curvature spheres in hyperbolic and spherical manifolds.
method Analyzes rotational CMC spheres in HnimesR and SnimesR, proving stability and instability properties. result Rotational CMC spheres in HnimesR are always stable, while those in SnimesR with large mean curvature are stable and those with small mean curvature are unstable. The paper characterizes biharmonic maps between spheres using polynomial functions.
problem Characterizing biharmonic maps between spheres using polynomial functions.
method Proved a characterization formula and constructed biharmonic maps.
result Classification of all proper biharmonic quadratic forms from spheres.
Locally flat 2-spheres in CP2 with knot group Z2 are ambiently isotopic if homologous.
problem Determining when locally flat 2-spheres in CP2 are ambiently isotopic. method Using knot groups and homology, proving isotopy based on homology equivalence and combining with previous results.
result Locally flat 2-spheres in CP2 with knot group Z2 are ambiently isotopic if they are homologous. Study invariants of Z/p-homology 3-spheres from abelianization of mapping class groups.
problem Deciding and constructing invariants of Z/p-homology 3-spheres. method Formulating a criterion and using families of trivial 2-cocycles on the abelianization of the level-p mapping class group. result Disproved a conjectured extension of the Casson invariant for rational homology 3-spheres.
Analytic saddle spheres in S^3 are equators.
problem Characterizing saddle-shaped minimal surfaces in 3-sphere.
method Purely geometric approach, no PDE imposed.
result Analytic saddle spheres in S^3 are equators.
There is a topological embedding ι:S1→R5 such that π3(R5∖ι(S1))=0. Therefore, no 3-sphere can be linked with ι(S1).
Bounds and constructions for Gromov-Hausdorff distance between spheres.
problem Calculating distances between spheres using Gromov-Hausdorff metric.
method Explicit constructions and topological ideas based on Borsuk-Ulam theorem.
result Lower bounds are tight for specific cases of sphere distances.
Study shows spheres in high dimensions have maximum volume if they are smooth and have a specific reach.
problem Finding the maximum volume of a smooth submanifold in Euclidean space.
method Using the concept of reach and volume, the study proves a volume inequality for submanifolds with a specific reach.
result Smooth submanifolds in Euclidean space have maximum volume if their reach is 1 and they are congruent to a unit sphere.
Authors construct hypertori with constant negative mean curvature in a sphere.
problem Constructing constant mean curvature hypertori in a sphere.
method Constructing two different constant mean curvature (2n−1)-dimensional hypertori in a 2n-dimensional sphere. result Two different constant mean curvature (2n−1)-dimensional hypertori with negative mean curvature in a 2n-dimensional sphere. The paper examines deformations of pseudoholomorphic curves in a nearly Kähler sphere.
problem Investigating rigidity and deformability of pseudoholomorphic curves in S6. method Analyzing moduli space of minimal surfaces isometric to pseudoholomorphic curves.
result Describes the moduli space of noncongruent minimal surfaces isometric to pseudoholomorphic curves.
This paper classifies Möbius homogeneous hypersurfaces in a sphere.
problem Classifying hypersurfaces in a sphere under Möbius transformations.
method Using Möbius transformation group to classify hypersurfaces.
result Möbius homogeneous hypersurfaces are completely classified.
In this paper we look at the knot complement problem for L-space Z-homology spheres. We show that an L-space Z-homology sphere Y cannot be obtained as a non-trivial surgery along a knot K⊂Y. As a consequence, we prove that knots in an L-space Z-homology sphere are determined …
In the present study we consider knotted spheres in Euclidean 4-space E4. Firstly, we give some basic curvature properties of knotted spheres in E4. Further, we obtained some results related with the conjugate nets and Laplace transforms of these kind of surfaces.
Paper classifies hypersurfaces in a sphere with specific curvature properties.
problem Classifying hypersurfaces in a sphere with constant curvature and mean curvature.
method Proved that such hypersurfaces must be isoparametric and identified specific types.
result Identified specific types of hypersurfaces: equatorial spheres, product of spheres, and Cartan's minimal hypersurface.
By only using spectral theory of the Laplace operator on spheres, we prove that the unit 3-dimensional sphere of a 2-dimensional complex subspace of C3 is a Ω-stable submanifold with parallel mean curvature, when Ω is the Kähler calibration of rank 4 of C3.
The study finds infinitely many p-harmonic maps between spheres for specific p and m.
problem Investigating p-harmonic maps between spheres for different dimensions and p-values.
method Analyzing rotationally symmetric p-harmonic maps and their stability.
result Existence of infinitely many p-harmonic self-maps of spheres for given p and m.
Extends rigidity results for Whitney spheres in higher dimensions.
problem Rigidity of Lagrangian submanifolds in complex and projective spaces.
method Analyzes Lagrangian submanifolds satisfying specific differential conditions.
result Characterizes Whitney spheres in Cn and CPn. Geodesic spheres in certain symmetric spaces are quantitatively stable under small perturbations.
problem Stability of geodesic spheres in symmetric spaces under perturbations.
method Quantitative stability analysis using spectral gap of the Laplacian on geodesic spheres.
result Geodesic spheres are uniformly stable with respect to small C1-volume preserving perturbations. Paper studies inscribed sphere and lines through centers of Apollonius spheres in n dimensions.
problem Tangency of spheres and lines through their centers.
method Lie sphere geometry and two-step construction of Apollonius spheres.
result Center of inscribed sphere coincides with point PX. Study defines hyper-dual spheres and ruled surfaces, proving geometric relationships.
problem Understanding geometric properties of hyper-dual spheres and ruled surfaces.
method Defined hyper-dual spheres, developed ruled surfaces, and established geometric relationships.
result Proved isomorphism between hyper-dual sphere and tangent bundle, and geometric interpretation of ruled surfaces.
We study generalized Killing spinors on round spheres Sn. We show that on the standard sphere S8 any generalized Killing spinor has to be an ordinary Killing spinor. Moreover we classify generalized Killing spinors on Sn whose associated symmetric endomorphism has at most two eigenva…
New Zoll families of minimal spheres found in spheres and projective spaces.
problem Finding new Zoll families of minimal spheres in various spaces.
method Equivariant constructions using Nash-Moser-Hamilton implicit function theorem.
result First examples of metrics on real projective spaces with Zoll families of minimal projective hyperplanes.
Minimal surfaces in spheres are classified based on a Ricci-like condition.
problem Classifying minimal surfaces in spheres.
method Using a Ricci-like condition equivalent to local isometry to a pseudoholomorphic curve in S5. result Minimal surfaces in spheres satisfying the Ricci-like condition are flat or direct sums of surfaces in the associated family of a pseudoholomorphic curve in S5. The paper constructs four-manifolds with lens space boundaries and explores sphere configurations in #nCP2.
problem Exploring configurations of spheres in #nCP2 and constructing four-manifolds with specific properties. method Constructing examples of simply connected four-manifolds with lens space boundaries using sphere plumbings in connected sums of CP2. result Examples of four-manifolds with lens space boundaries and configurations of spheres with self-intersection number 20.
Generalized Thurston's characterization for branched coverings of the 2-sphere.
problem Characterize branched coverings of the 2-sphere.
method Introduced local balance and operations against balanced graphs.
result New proof of a theorem by Eremenko-Gabrielov-Mukhin-Tarasov-Varchenko.
We show that if an open set in Rd can be fibered by unit n-spheres, then d≥2n+1, and if d=2n+1, then the spheres must be pairwise linked, and n∈{0,1,3,7}. For these values of n, we construct unit n-sphere fibrations in R2n+1.
The article recovers the Smale conjecture on a Sasakian 3-sphere using Legendrian mean curvature flow.
problem Recovering the Smale conjecture on a Sasakian 3-sphere.
method Using Legendrian mean curvature flow to deform area-preserving contactomorphisms to isometries.
result Obtained the minimal Legendrian graph in S² × S³.
In this paper, we prove some convergence theorems for the mean curvature flow of closed submanifolds in the unit sphere Sn+d under integral curvature conditions. As a consequence, we obtain several differentiable sphere theorems for certain submanifolds in Sn+d.
We introduce a class of minimal submanfolds Mn, n≥3, in spheres Sn+2 that are ruled by totally geodesic spheres of dimension n−2. If simply-connected, such a submanifold admits a one-parameter associated family of equally ruled minimal isometric deformations that are genuine. As for compact exa…
New method for triharmonic maps to spheres in various dimensions.
problem Creating triharmonic maps to spheres in different dimensions.
method Construction method based on eigenmaps and suitable deformations.
result Existence of triharmonic maps from Rm∖{0} into spheres. The study identifies holomorphic sections on jet spaces of the Riemann sphere.
problem Holomorphic sections on jet spaces of the Riemann sphere.
method Identifying a class of holomorphic sections of line bundles.
result Identified holomorphic sections on jet spaces of the Riemann sphere.
The paper studies Pansu spheres in a sub-Riemannian 3-sphere and their area-minimizing properties.
problem The study of Pansu spheres and their area-minimizing properties in a sub-Riemannian 3-sphere.
method Calibration arguments.
result The closed half-spheres of S0 with boundary C0 minimize sub-Riemannian area among compact C1 surfaces with the same boundary. In this paper, the singular-value decomposition theory of complex matrices is explored to study constantly curved 2-spheres minimal in both CPn and the hyperquadric of CPn. The moduli space of all those noncongruent ones is introduced, which can be described by certain complex symmetric matrices…
We introduce and study a new class of homotopy spheres called Farrell-Jones spheres. Using Farrell-Jones sphere we construct examples of closed negatively curved manifolds M2n, where n=7 or 8, which are homeomorphic but not diffeomorphic to complex hyperbolic manifolds, thereby giving a partial answer to a que…
New types of Delaunay hypersurfaces found in spheres.
problem Characterizing Delaunay hypersurfaces in spheres.
method Analyzing hypersurfaces in Sn with n≥3. result Found new types of Delaunay hypersurfaces, including embedded ones.
Minimal surfaces in S3(2) linked to vector fields on punctured sphere.
problem Connecting minimal surfaces in S3(2) to vector fields on a punctured sphere.
method Established a correspondence between minimal surfaces and area-minimizing vector fields.
result Stability relation for Lawson cylinders in S3(2).
There exists a well known construction which allows to associate with two hyperbolic affine spheres fi:Mini→Rni+1 a new hyperbolic affine sphere immersion of I×M1×M2 into Rn1+n2+3. In this paper we deal with the inverse problem: how to determine from properties …
Falsehood of Pólya's conjecture for spheres shown.
problem Disproving Pólya's eigenvalue conjecture for spheres.
method Comparison of Laplace spectrum and Weyl function of spheres.
result No analogue of Pólya's conjecture holds for spheres.
The paper classifies smooth structures on product manifolds of 3-connected 8-manifolds with spheres.
problem Classifying smooth structures on product manifolds.
method Computational and classification methods for concordance and diffeomorphism.
result Diffeomorphism classification of MimesS1 for specific M and k. Study on minimal two-spheres in complex hyperquadric, proving non-congruence of constant curvature spheres.
problem Classifying minimal two-spheres of constant curvature in complex hyperquadric.
method Construction of non-homogeneous constant curved minimal two-spheres and classification theorem.
result Minimal two-spheres of constant curvature in Q4 are not congruent. The cosmetic surgery conjecture is a longstanding conjecture in 3-manifold theory. We present a theorem about exceptional cosmetic surgery for homology spheres. Along the way we prove that if the surgery is not a small seifert Z/2Z-homology sphere or a toroidal irreducible non-Seifert surgery then t…
Study constant and almost constant curvature spheres in hyperbolic space.
problem Existence of spheres with constant or almost constant mean curvature in hyperbolic space.
method Nondegeneracy result and sufficient conditions on prescribed functions.
result Existence of curves of embedded spheres with specified mean curvature.
Proves spheres with bounded curvatures must contain a unit ball.
problem Proving spheres with bounded curvatures enclose a unit ball.
method Analyzing topological spheres in R^3 with bounded normal curvatures.
result Spheres with normal curvatures bounded by 1 must contain a unit ball.
We construct a large class of pathological n-dimensional topological spheres in Rn+1 by showing that for any Cantor set C⊂Rn+1 there is a topological embedding f:Sn→Rn+1 of the Sobolev class W1,n whose image contains the Cantor set C.
Optimal inequality on sphere for convex bodies.
problem Bounding the spherical measure of a convex body's intersection with a plane orthogonal to its centroid.
method Proving an inequality on the sphere using convex geometry.
result The inequality is optimal with a constant of \((1-1/n)^{n-1}\).
Paper studies equatorial concentration of measure in sphere immersions and submersions.
problem Equatorial concentration of measure in sphere immersions and submersions.
method Analyzes concentration of measure phenomena in the sphere.
result Describes an equatorial concentration of measure for minimal immersions and submersions.
Explicitly constructs CR regular embeddings of spheres in complex spaces.
problem Embedding spheres in complex spaces with CR regularity.
method Generalizes Ahern and Rudin's construction to higher dimensions.
result Odd dimensional spheres admit CR regular embeddings in complex spaces if and only if the dimension is even.
Paper studies rigidity of translation surfaces in 3D sphere using quaternionic product.
problem Rigidity of translation surfaces in S3. method Introduced an associated frame for curves in S3; described local geometry; used curvature and torsion of generating curves. result Rigidity results for minimal and constant mean curvature surfaces in S3.